1. Field of the Invention
The present disclosure relates to assembly of bladed disks. More specifically, the present disclosure relates to an assembly device that installs shrouded or other high aspect ratio blades in a turbine or compressor disk.
2. Description of Related Art
The blades of turbine disks have blade roots that are installed into broach slots on the outside diameter of the turbine disk. The blades have a curved airfoil portion extending radially outward from the blade root and a shroud on the distal end of the airfoil portion. When the blades are installed in the turbine disk, the shrouds on the ends of the blades abut with the shrouds of adjacent blades, which increases damping and thereby reduces blade flutter. But, the shrouded blade design makes the blades difficult to install because they are designed to twist when being seated into place.
The installation of shrouded blades in a turbine disk is traditionally accomplished by hammering the roots of the blades into the turbine disk with a plastic mallet. The roots of the blades are seated in the disk by hammering them down into the broach slots, which may be configured in a fir tree shape. The blades are driven into the broach slots in a circular manner around a table/wheel that holds the turbine disk in place while the blades are installed. This is compounded many times by seal strip materials on the inner shrouds of the blades. This method of installation of turbine blades is relatively time consuming.
Additionally, physically hammering the blades can damage the blades themselves and other parts of the turbine disk. For example, when blades are manually hammered into the disk, the depth of penetration of the blade root into the broach slots is not controlled and blade roots can bind, jam or be positioned improperly.
Accordingly, there is a need for a turbine blade assembly device to install shrouded blades into a turbine disk that provides positive control of the engagement between the turbine blade root and the broach slot on the turbine disk. A device is needed that ensures the blade is angled properly to prevent binding of the blade roots and does not require hammering.